Methods, pharmaceutical compositions, and kits are provided which includes accurately sampling a RNA from a tissue of an animal and analyzing RNA in the tissue of the animal as an indicator of physiological state, infectious disease, neoplastic disease, autoimmune disease, inflammatory disease, cardiovascular disease, atherosclerotic disease, or neurological disease in the animal. A method is provided which includes administering at least one compound to an animal wherein the at least one compound is configured to prevent the cleavage of at least one tissue RNA by a ribonuclease. The method further includes collecting a sample of at least a portion of tissue from the animal.